Pelvic floor disorders in females include two under recognized, yet potentially devastating manifestations, fecal incontinence (FI) and obstructed defecation (OD). Current pathophysiological paradigms focus on spasm of the puburectalis and external sphincters in OD, and anal sphincter trauma (usually obstetric) or pudendal neuropathy in F1. Current diagnostic tests for OD (anorectal manometry, defecography, rectal balloon expulsion) are neither standardized nor reproducible; endoanal ultrasound is suboptimal for detecting sphincter defects in F1. The role of rectal compliance, rectoanal compliance (i.e. marked urgency), and/or diminished recto-anal sensation (e.e., lack of awareness of incontinence) and ii) objective evidence of anal sphincter weakness, reduced rectal compliance with increased sensitivity, or diminished anal sensation. Our central HYPOTHESES are that" i) FI is a heterogeneous disorder in which patients demonstrate one or more pathophysiological mechanisms: these include anal sphincter weakness, reduced rectal compliance, abnormal recto-anal sensation, excessive perineal descent and puborectalis dysfunction with failure to maintain the recto-anal sling, ii) ID is due to failure of relaxation of the puborectalis and/or external anal sphincter during straining, a disturbance which is reversible by biofeedback therapy. There are 3 specific aims: 1) To validate that novel pelvic MR imaging can define static and dynamic anatomy, thus quantify the contributions of anal sphincter defects, excessive perineal descent, puborectalis dysfunction, and pelvic ligamentous laxity to FI, 2) In FI, to determine if the symptom of rectal urgency predicts reduced rectal compliance and increased sensitivity to rectal distention, while the lack of patient awareness of FI predicts diminished recto-anal sensation, 3(a) To quantify puborectalis dysfunction in OD using pelvic MR and 3(b) to assess the effect of biofeedback therapy on MRF indices of puborectalis dysfunction in MD. This project will integrate clinical assessments, a validated questionnaire for F1, reproducible measurements of rectal compliance and sensation, a novel assessment of anal temperature and translational applications of ultrafast MR imaging. We propose to study 60 female patients with F1 and 25 age-matched controls (Specific Aims 1 and 2), and 60 female patients with OD and 25 age- and gender-matched controls (Specific Aim 3). We anticipate these studies will demonstrate that static and dynamic disturbances of pelvic floor function, rectal compliance and rectoanal sensations are important in OD and F1, thus providing a basis for novel diagnostic methods and therapeutic approaches.